well if by cardio you mean running then I may possibly know what it is.Some runners call them stitches but its really just a cramp what you should do to get rid of it is don't drink water before you go because all of the water will rush to a side and make it cramp(or atleast thats what my science teacher told us) and you shouldnt really eat a lot before going running because it can cause them to especially things that are greasy like pizza garlic fingers and stuff like that can cause bad ones. so basically just don't really drink water before you go or drink it like 30 minutes earlier and dont fill up on food.But you can still get them sometimes I just get them when Im walking. but the above will help a lot with not getting them and its nothing to do with you kidney's I know that it feels like someone is scraping a knife around in there and is gonna rip your kidney area out but its just cramps your getting hope that helps

EDIT: oh and if you keep running it just gets worse so stopping and taking a breather helps but you c an just keep running the pain goes away relativley fast afterword anyway.

I suspect stitches from experience! Cramps. Yeh. Breathe on that cardio workout. Deep. Through your belly and exhale completely. Please don't hyper-ventilate though. Best to just slow the cardio down a few minutes then come stop for a while if you feel you need to. Breathe and stretch the area out gently supporting your back and sides with your hands. No jerky movements. When its gone start again. That works for me. I have never heard of water around the sides being a problem! Keep sipping the water! We need it to do all this training and sweating! xxx

It is important to drink water prior to performing any enduring cardio. Sipping can prevent the upset stomach, or drinking the proper amount a half hour before. (When I did cross country we would drink alot of water 30 minutes before the race so we were well hydrated, and we didnt get upset stomachs).

yep, ikklehen is right. Inhale through your nose, and exhale deeply through your mouth. Focus on this as soon as you feel the cramp coming on. If it doesn't go away, exhale even more deeply, maybe even completely each breath. Should work. Does for me anyway.

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